Electrodeposited Copolymers Based on 9,9'-(5-Bromo-1,3-phenylene)biscarbazole and Dithiophene Derivatives for High-Performance Electrochromic Devices

• Published in: Polymers Vol. 13; no. 7; p. 1136
• Main Authors: Kuo, Chung-Wen, Chang, Jui-Cheng, Chang, Jeng-Kuei, Huang, Sheng-Wei, Lee, Pei-Ying, Wu, Tzi-Yi
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 02.04.2021; MDPI
• Subjects: absorption spectra; Benzene; Circuits; Copolymers; Electrochromic cells; electrochromic device; Electrochromism; electrodeposition; Electrodes; Electrolytes; Hydrocarbons; Optical memory (data storage); Oxidation; Polymers; redox stability; Response time; transmittance; United States > US; Japan; electrochromic device; electrodeposition; transmittance; absorption spectra; redox stability
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym13071136

A 1,3-bis(carbazol-9-yl)benzene derivative (BPBC) was synthesized and its related homopolymer (PBPBC) and copolymers (P(BPBC- -BT), P(BPBC- -CDT), and P(BPBC- -CDTK)) were prepared using electrochemical polymerization. Investigations of polymeric spectra showed that PBPBC film was grey, iron-grey, yellowish-grey, and greyish-green from the neutral to the oxidized state. P(BPBC- -BT), P(BPBC- -CDT), and P(BPBC- -CDTK) films showed multicolor transitions from the reduced to the oxidized state. The transmittance change (Δ ) of PBPBC, P(BPBC- -BT), P(BPBC- -CDT), and P(BPBC- -CDTK) films were 29.6% at 1040 nm, 44.4% at 1030 nm, 22.3% at 1050 nm, and 41.4% at 1070 nm. The coloration efficiency ( ) of PBPBC and P(BPBC- -CDTK) films were evaluated to be 140.3 cm C at 1040 nm and 283.7 cm C at 1070 nm, respectively. A P(BPBC- -BT)/PEDOT electrochromic device (ECD) showed a large Δ (36.2% at 625 nm) and a fast response time (less than 0.5 s), whereas a P(BPBC- -CDTK)/PEDOT ECD revealed a large (534.4 cm C at 610 nm) and sufficient optical circuit memory.